.horizontal-center {
      width: 100%;
      display: flex;
      justify-content: center;
      flex-wrap: wrap;
}

.vertical-center {
      width: 100%;
      display: flex;
      align-self: center;
      flex-wrap: wrap;
}

.center {
      width: 100%;
      display: flex;
      justify-content: center;
      align-self: center;
      flex-wrap: wrap;
}

.footer-container {
      position: fixed;
      bottom: 6rem;
      width: 100%;
      z-index: -1;
      .flex-container {
            display: flex;
            width: 100%;
            justify-content: center;
            .music-box {
                  width: 60%;
                  margin-top: 40rem;
                  .control-panel {
                        width: 100%;
                        justify-content: space-between;
                        display: flex;
                        .songinfo {
                              display: flex;
                              .song-cover {
                                    img {
                                          width: 4.8rem;
                                          height: 4.8rem;
                                    }
                              }
                              .song-detail {
                                    display: flex;
                                    flex-direction: column;
                                    justify-content: space-between;
                                    margin-left: 1rem;
                                    .songname {
                                          font-size: 2.4rem;
                                          line-height: 2.4rem;
                                          margin-top: 0.2rem;
                                    }
                                    .songwriter {
                                          font-size: 1.6rem;
                                          line-height: 1.6rem;
                                          margin-bottom: 0.2rem;
                                    }
                              }
                        }
                        .control-items {
                              display: flex;
                              button {
                                    width: 3.2rem;
                                    height: 3.2rem;
                                    background-color: transparent;
                                    border: none;
                                    outline: none;
                                    cursor: pointer;
                                    background-size: cover;
                                    transition: all ease 0.3s;
                              }
                              .control-item {
                                    display: flex;
                                    align-items: center;
                                    justify-content: center;
                                    width: 4.8rem;
                                    height: 4.8rem;
                                    background-color: black;
                                    background-color: rgba(0, 0, 0, 0.6);
                                    margin-left: 0.4rem;
                              }
                              .play-pause {
                                    button {
                                          background-image: url('../img/pause.svg');
                                    }
                              }
                              .next {
                                    button {
                                          background-image: url('../img/next.svg');
                                    }
                              }
                              .playlist {
                                    a {
                                          width: 3.2rem;
                                          height: 3.2rem;
                                          background-color: transparent;
                                          cursor: pointer;
                                          background-size: cover;
                                          background-image: url('../img/playlist.svg');
                                    }
                              }
                        }
                  }
                  .progress-bar {
                        width: 100%;
                        height: 0.4rem;
                        margin-top: 1rem;
                        background-color: white;
                        .progress {
                              width: 0%;
                              height: 0.4rem;
                              background: -webkit-radial-gradient(#a3e736, #7661f0);
                              transition: all ease 0.3s;
                        }
                  }
            }
      }
}
